1. Field of the Invention
Embodiments of the invention generally relate to the field of radar system antennas, and more specifically to patch antenna arrays suitable for use in ultra-wide-band radar applications.
2. Discussion of Related Art
Radar is used in many applications to detect target objects such as airplanes, military targets, and vehicles. More recently, radar systems have been implemented in automobiles. Automotive radar systems are known for use in helping drivers to park their cars, to follow traffic at a safe distance, and to detect driving obstacles. In such applications, when the radar system detects an obstacle or the slowing down of traffic in front of the vehicle, it may issue a warning to the driver, such as a beep or warning light on the dashboard, and/or actually control the vehicle in some way, such as by applying the brakes, in order to avoid an accident.
For example, a radar system may detect the range (i.e., distance) to a target object by determining the roundtrip delay period between the transmission of a radar signal and the receipt of the signal returning back to the radar after it bounces off of the target object. This round-trip delay, divided in half and then multiplied by the speed of the radiation, c, gives the distance between the radar system and the target object (assuming the transmitting antenna and the receiving antenna are the same antenna or very close to each other).
As can be appreciated, it would be desirable to provide radar antenna structures for automobile applications that can be implemented in a compact volume, and which also can be provided at a low cost.